The present invention relates generally to image forming devices, and more particularly to a roller for routing print media through an image forming device.
A conventional image forming device for printing and/or duplicating characters and/or other images onto print media includes one or more print media transport assemblies for routing the print media through a print media path. Typically, the print media transport assemblies each include one or more rollers each mounted on a shaft for contacting the print media and routing the print media through the print media path of the image forming device. Often, the rollers are formed of a solid rubber material.
By forming the rollers of a rubber material, the rollers provide desirable characteristics such as an adequate coefficient of friction, high wear resistance, durability, and ease of manufacture. For example, by forming the rollers of a rubber material, the rollers provide a delicate coefficient of friction which contacts the print media and routes the print media effectively through the image forming device without damage to the print media. In addition, by forming the rollers of a rubber material, the rollers can be formed with conventional molding techniques and easily machined to form concentric rollers.
Unfortunately, forming the rollers of a solid rubber material is relatively expensive. Since each print media transport assembly of the image forming device often includes multiple rollers, the expense of individual rollers is quickly compounded. The total cost of the rollers, therefore, can add significantly to the cost of the image forming device.
Accordingly, a need exists for a roller for use in an image forming device which provides the advantages of a solid rubber roller, yet is less expensive to produce without impacting an ease of manufacturability and/or throughput or print quality of the image forming device.
One aspect of the present invention provides a roller adapted for contacting print media in an image forming device. The roller includes a tubular core formed of a first material and having an inner surface and an outer surface, and a sleeve formed of a second material and surrounding a portion of the tubular core. The sleeve includes an inner portion surrounding a portion of the inner surface of the tubular core and an outer portion surrounding a portion of the outer surface of the tubular core.
In one embodiment, the second material is a rubber material. In one embodiment, the first material is a plastic material.
In one embodiment, the tubular core has a first end and a second end, wherein the inner portion of the sleeve extends between the first end and the second end of the tubular core. In one embodiment, the outer portion of the sleeve extends between the first end and the second end of the tubular core.
In one embodiment, the outer portion of the sleeve includes a first portion extending from the first end of the tubular core toward the second end of the tubular core and a second portion extending from the second end of the tubular core toward the first end of the tubular core. As such, the first portion and the second portion are spaced axially on the tubular core.
In one embodiment, the inner portion of the sleeve has an inner surface and an outer surface. As such, the outer surface of the inner portion contacts the inner surface of the tubular core.
In one embodiment, the outer portion of the sleeve has an inner surface and an outer surface. As such, the inner surface of the outer portion contacts the outer surface of the tubular core and the outer surface of the outer portion is adapted to contact the print media.
In one embodiment, the tubular core has a first end and a second end, and the sleeve further includes at least one end portion surrounding a portion of at least one of the first end and the second end of the tubular core. In one embodiment, the at least one end portion of the sleeve includes an inner surface and an outer surface. As such, the inner surface of the at least one end portion contacts the at least one of the first end and the second end of the tubular core. In one embodiment, the at least one end portion of the sleeve has a plurality of openings formed therein. As such, the tubular core is accessible through each of the openings.
Another aspect of the present invention provides a method of forming a roller for an image forming device. The method includes providing a tubular core formed of a first material and having an inner surface and an outer surface, and surrounding a portion of the tubular core with a sleeve formed of a second material. Surrounding the tubular core with the sleeve includes surrounding a portion of the inner surface of the tubular core with an inner portion of the sleeve and surrounding a portion of the outer surface of the tubular core with an outer portion of the sleeve.
Another aspect of the present invention provides a print media transport assembly. The print media transport assembly includes a shaft and at least one roller mounted on the shaft. The at least one roller includes a tubular core, an inner sleeve surrounding a portion of an inner surface of the tubular core, and an outer sleeve surrounding a portion of an outer surface of the tubular core. As such, the inner sleeve contacts the shaft. In addition, the tubular core is formed of a first material and the inner sleeve and the outer sleeve are formed of a second material.
Another aspect of the present invention provides an image forming device including at least one print media transport assembly adapted for routing print media therethrough. The at least one print media transport assembly includes a shaft mounted in the image forming device and at least one roller mounted on the shaft. The at least one roller is adapted for contacting the print media and includes a tubular core, an inner sleeve surrounding a portion of an inner surface of the tubular core, and an outer sleeve surrounding a portion of an outer surface of the tubular core. As such, the inner sleeve contacts the shaft and the outer sleeve is adapted for contacting the print media. In addition, the tubular core is formed of a first material and the inner sleeve and the outer sleeve are formed of a second material.
The present invention provides a roller for a print media transport assembly of an image forming device. The roller includes a tubular core and a sleeve of rubber material surrounding the tubular core. As such, the sleeve of rubber material contacts and routes print media through a print media path of the image forming device and frictionally couples the roller to a shaft of the print media transport assembly when mounted thereon.